How Can Swelling In The Foot Due To A Rusty Nail Injury Be Treated?

A year ago, my husband stepped onto a rusty nail in some undergrowth. It went through trainers socks and punctured his foot. He developed swelling of the foot and ankle, temperature and redness of the face. He went to the doctor 2 days after and was given a tetanus injection, 25mg anti biotics and antiseptic foot wash. The tablets didn't clear it up even after 2 weeks, his stomach felt sickly by then too. The dr eventually after 2 weeks of the other tablets, gave him amoxcyllin? anti biotic 500mg and it seemed to clear up, swelling went down and he felt better. A year on and the foot is swollen again, stomach sickly rash on face and he has been given the same 25mg anti biotics as he was gave initially and they aren't doing anything again, the foot is still swollen, even after antiseptic bathe. he has red rash on his face his forelegs are itching and red and he feels unwell.